During the repair of a wooden structure that has suffered from rot, it is not only necessary to remove the wood that has been affected by rot, but it is also important to treat and/or strengthen the area before applying a repair product such as a wood filler. This is necessary so a strong bond can be formed by the wood filler to the area to be repaired and also so any wood softened by rot that could not be easily removed by scraping will be structurally strong before the repair is made.
Presently there are a few rotted wood stabilizers on the market. These compositions can generally be classified into one of two categories. The first category comprises solventborne (i.e. containing organic liquids as the solvent, such as alcohols, acetones, ketones, etc.) rotted wood stabilizer compositions. The second category comprises waterborne rotted wood stabilizer compositions, such as PC Petrifier Rotted Wood Hardener sold by Protective Products Corp. of Allentown, Pa. 18102.
The current leader in the solventborne rotted wood stabilizer market is Bondo Corporation of Atlanta, Ga. Bondo's wood rot stabilizer product is an extremely flammable rotted wood stabilizer that is a polystyrene resin dissolved in acetone and methyl ethyl ketone (MEK). In essence, the Bondo's stabilizer is little more than “airplane glue” thinned down to a very low viscosity liquid having relatively low solids by weight percent. The low-viscosity Bondo product can be poured from a container and will flow into a crevice of rotted wood. Upon drying, it will penetrate the wood and strengthen the rotted wood area. However, multiple treatments are required, primarily because organic solventborne stabilizers have a lower solids content, which delivers low volume of solids upon application. Therefore, multiple applications or coats are often necessary to fully treat a repair area.
Solventborne products allow for fast evaporation and will dry at the same rate, independent of atmospheric humidity. However, this advantage is offset by the disadvantages. In addition to the fact that multiple coatings are required in order to strengthen the rotted wood area, known solventborne rotted wood stabilizers are extremely flammability and create a safety hazard. Fumes from solventborne rotted wood stabilizer compositions present an immediate exposure hazard to the users and others in close proximity to the application, as well as a flame hazard due to the high flammability and low flash point of the solvents used in the composition. Additionally, the use of organic solvents in known compositions presents an environmental hazard in the form of potential product spills, improper application, and leaching from treated wood into the surrounding environment
With respect to waterborne wood stabilizers, the MSDS for Protective Coating's PC Petrifier™ brand wood hardener indicates that it is a water-based mixture of a urethane hybrid polymer, acrylic latex, sodium dioctylsulfosuccinate, and 1-methyl-2-pyrrolidinone. The labeling and advertising for PC Petrifier™ indicates that it is not recommended for structural repairs, and therefore it does not address the need for a water-based wood stabilizing composition that can effect a structural repair. Additionally, without a film-forming agent and biocide, repairs using known waterborne products such as the PC Petrifier™ product are compromised by poor penetration and inadequate protection against recurring infestation of mold and other organisms.